Radio-wave spectrum is a kind of limited strategic resource. With the development of wireless communication services, it is an inevitable trend that channel bandwidth of wireless communication will be reduced to meet the requirement of the continuously increasing amount of users. For this reason, the channel bandwidth for wireless radios is necessitated to be transited from 25 kHz to 12.5 kHz or 6.25 kHz. The wireless radio communication outside China is developing toward a 6.25 kHz narrow-band technique, which is the developing direction for the international digital radios.
To popularize the application of the narrow-band digital technique in the market better, European Telecommunications Standards Institute (ETSI), Conference Europe of Post and Telecommunications (CEPT), American Federal Communications Commission (FCC), American Railroads Association, Japanese Association of Radio Industries and Businesses (ARIB) and the like are actively promoting the effective utilization of the spectrum resources and actively supporting manufacturers of radio devices to develop systems and devices with high frequency spectrum utilization efficiency, and great advance has been made. FCC 08-127 specifies that authentication of any devices having the 25 kHz-mode is forbidden from Jan. 1, 2011, and conversion into the 6.25 kHz-mode by the licensee is encouraged.
Presently, in the decision of conferences about the radio spectrum resources made by China radio-wave spectrum planning department, it is mentioned that approbation of analog radio model numbers will be stopped in China. Future digital radios in China have two standards: 12.5 kHz bandwidth standard and 6.25 kHz bandwidth standard.
To smoothly transit between the 12.5 kHz standard and the 6.25 kHz standard so as to make the most of the existing devices and reduce the cost for device replacement, it is necessary to realize free inter-communication between radios with different bandwidths under the same standard.
The existing wireless communication devices such as the radios support the digital or analog 12.5 kHz adaptive identification. Such devices achieve the digital and analog adaptive identification by identifying a synchronization frame.
The inventors discover that the prior art has the following disadvantages:
1) Adaptive identification between different bandwidths is not supported;
2) Adaptive identification between digital modes is not supported;
3) Inter-communication between the 6.25 kHz standard and the 12.5 kHz standard can not be realized in the case of consistent air interface protocols; and
4) A host can support only one standard.